The two had been at loggerheads the night before, at an election event in Willowfield Church.

East Belfast is proving to be one of the most bitter election fights, with the DUP determined to win back the seat that Ms Long took from DUP leader Peter Robinson in 2010.

While the two contenders emphasised last night that they did not "detest" each other, minutes later they were sparring again.

Ms Long told the audience that despite media speculation, she did not hate Mr Robinson, dismissing their clashes as "playground stuff".

Her DUP rival nodded in agreement and said: "Absolutely right".

But when it came to how both representatives spoke about the constituency, a row quickly developed between the pair.

Mr Robinson accused Ms Long of being negative, citing her recent comments that East Belfast could lose out on manufacturing jobs if the UK were to leave the EU. He also took issue with how she highlighted the area's problems with paramilitarism in the Belfast Telegraph earlier this year and her concerns about Tesco leaving Connswater Shopping Centre.

Ms Long hit back furiously, saying she would not airbrush over problems and that she was being realistic.

"You need to talk positively," Mr Robinson urged Ms Long.

The MP replied: "We need to talk realistically".

Mr Robinson also sparked surprise when he distanced himself from comments by his party leader Peter Robinson. The First Minister had suggested that Ms Long could "dry her eyes" if she loses.

But Gavin Robinson refused to endorse that comment: "Listen to me... You will not hear comments like that from me."

Both politicians started with opening speeches declaring their love for the constituency.

Mr Robinson won the coin toss and immediately spoke of his love for East Belfast, describing it as "iconic", and his pride at representing part of the constituency on Belfast City Council.

Ms Long described the Strand Arts Centre venue, where she had watched films as a child, as a metaphor for East Belfast - in transition and changing for the better.

The pair disagreed over whether cutting the number of days the Union flag is flown from Belfast City Hall is still a big issue. Mr Robinson told the audience that the flag issue was still prevalent and was being brought up on the doorsteps.

But Ms Long said she was finding that the flag was brought up much less often by voters in this election than it had been last year before the European and council polls. The debate was organised by political blog Slugger O'Toole along with polling company LucidTalk and Chambre Public Affairs.